I thought the thing on the back was a saddle for Mario ever since SMW days, which is odd - Yoshi just has that on his back when he hatches.
I also don't really care for the uber-cute Yoshi. I like the grittier characters for Brawl because...well it is for fighting after all.
Besides, the Smash series seems to contain the best character models for Nintendo mascots, and I always wondered why they aren't just used everywhere. I remember thinking the Sunshine Mario didn't compare to the Smash version (let's not even mention the abortions that are the Mario Party versions).
I don't even think "grittier" needs to be done. Donkey Kong from Jungle Beat was awesome - he had this sort of anxious hero look to him, with his looks of semi-worry/"We're in a tight spot" sort of thing. These were counterbalanced (very well, I might add) by his crazy smiles. I thought that was the perfect persona for him to embody, and he looked tens time better than the Smash version, which was a lot more goofy. I guess I just like it when the personalities seem a little less extreme one way or the other.
Oh well. I'm not going to let it bother me.